AINEWS
Why every browser on your iPhone is really Safari in disguise
Microsoft's Edge team put a number on Apple's engine rule: a prototype ran Apple's own speed test 28.6 percent faster than Safari on the same iPhone.
Microsoft's Edge team put a number on Apple's engine rule: a prototype ran Apple's own speed test 28.6 percent faster than Safari on the same iPhone.
Every browser on your iPhone, including Chrome, Firefox, and Edge, is, at the engine level, the same software as Safari. Apple requires it. Microsoft's Edge team says the price of that rule shows up in seconds of load time, and on June 15 it put a number on the cost: on Apple's own Speedometer 3.1 browser benchmark, a prototype Blink-based browser ran 28.6 percent faster than Safari on the same device.
The prototype is Kyle Pflug's "Test Drive: Blink on iOS", published on LinkedIn on June 15. Pflug, a group product manager on Microsoft's Edge Web Platform team, ran the tests on his personal iPhone 17 Pro Max running iOS 26.5.1, not in a lab. He flagged the build as a research prototype, not a product announcement, and the numbers as preliminary. On Speedometer 3.1 the Blink build scored 49.27 against Safari's 38.3. On JetStream 3, which measures JavaScript and WebAssembly execution, the gap narrowed to 13.1 percent (306.35 versus 270.9). On MotionMark 1.3.1, a graphics-rendering test, the difference shrank to roughly 2 percent.
The point of the post was not just the scores. Pflug argued the gap is what you would expect when one engine faces no competition. Rick Byers, a principal engineer on Google Chrome, amplified the result the same day: "Given how Chromium and WebKit are always vying for the top spot in Speedometer on macOS, it's really striking how big the gap is on iOS! ... IMHO this is what you should expect to see when there's a lack of competition."
The Register's write-up called the headline number a "WebKit performance tax," riffing on the long-running "Apple tax" framing around App Store commissions. That framing is a Microsoft argument, not an independent verdict, and Microsoft has skin in the game: a real non-WebKit Edge on iOS would be a different product from the one iPhone users download today, and Microsoft would have to rebuild its iOS audience from scratch.
WebKit is the engine that draws web pages: it parses HTML, runs JavaScript, applies CSS, and lays out what you see on screen. Apple's App Store rules require every browser distributed through it on iPhone and iPad to use WebKit, which means Chrome, Firefox, Edge, and Brave are all, underneath their custom skins, the same rendering engine that powers Safari. On macOS, by contrast, browsers can ship their own engines, which is why Chrome on Mac generally outperforms Chrome on iPhone in the same benchmark.
The practical consequences go beyond speed. Pflug's prototype surfaced missing web features that are already in Chromium and Gecko (the engines under Chrome and Firefox) but absent from WebKit: corner-shape, interpolate-size, calc-size, Temporal, reading-flow, Scheduler, moveBefore, and requestIdleCallback. Each is a small thing on its own. Together they are the gap between what a web developer can build on a desktop browser and what they can build for an iPhone user.
Apple's defense of the rule has not changed in years. Requiring every browser on iOS to use WebKit, the company says, lets it apply security patches and performance fixes across the whole browser population at once, and keeps battery life and memory usage consistent with the rest of the operating system. That argument is not a straw man. Sandbox escapes, speculative-execution side channels, and memory-corruption bugs in JavaScript engines have been a recurring class of iOS vulnerability for a decade, and a single rendering engine does limit the surface area Apple has to harden.
The argument has limits, though. Apple has run Speedometer alongside WebKit's own developers for years, and 28.6 percent on Apple's own test suite, even from a preliminary prototype on one engineer's personal device, is the kind of number the company normally contests in public. Apple declined to comment for The Register's story. The silence is itself a data point.
The WebKit-only rule has been under legal pressure in Europe since 2024. The EU's Digital Markets Act, the competition law aimed at platform gatekeepers, theoretically allows EU-based developers to ship browsers with non-WebKit engines. Apple responded with BrowserEngineKit, a March 2024 framework that exposes engine internals to third-party browser makers. Two and a half years later, no vendor has shipped a commercial alternative.
Italy's competition authority opened a DMA-related investigation in June 2026, and the UK's Competition and Markets Authority has Apple's browser rules in its final decision report. Mozilla, quoted in The Register's piece, frames engine diversity as the structural question: which actors shape how web standards are implemented, how security and privacy protections are enforced, and how the open web evolves. Open Web Advocacy, a campaign group that has pushed the engine question in front of European regulators for years, told The Register that opening iOS to competing engines is the "most critical intervention" the European Commission could make.
Mozilla's own numbers show the regulatory pressure is moving users. Its May 2026 disclosure that browser-choice screens in Europe have shifted roughly six million users toward Firefox is a small fraction of the mobile browser market, but it is also the first time a Firefox-shaped choice has appeared at iOS scale.
Pflug's prototype is not the first. Google and Mozilla both built prototype Blink and Gecko iOS browsers in 2023. Neither shipped. The reasons are technical and commercial. BrowserEngineKit, even with two and a half years of work, still has bugs that Microsoft's engineers have catalogued in a public Chromium hotlist. A Blink-based Edge would have to ship as a separate app, which means Apple users who currently have Edge installed would have to download it again, and Edge's iOS audience is small to begin with.
Microsoft has not said it plans to ship a Blink-based Edge. It has said the prototype shows the gap is real. Whether the gap closes depends less on Microsoft's engineering and more on whether European regulators force Apple to widen BrowserEngineKit, or open the door to competing engines outright.